Joaquin Guzman, the powerful drug cartel leader also known as “El Chapo” managed to break out of a Mexican prison using a sophisticated tunnel. Guzman heads the Sinaloa Cartel, which the US government describes as one of the world’s “most prolific, violent, and powerful drug cartels.”

In a series of tweets Sunday night and Monday morning, Trump directly challenged Guzman:

“I’m fighting for much more than myself. I’m fighting for the future of our country which is being overrun by criminals.” the real-estate magnate said about the threat. “You can’t be intimidated. It’s too important.”

Business Insider reached out to the FBI press office, and we will update this post if we hear back.